From nobody Fri Jun 7 00:27:02 2024 X-Original-To: bugs@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4VwMTL57Byz5NLZM for ; Fri, 07 Jun 2024 00:27:02 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4VwMTL3ZpGz4HSJ for ; Fri, 7 Jun 2024 00:27:02 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1717720022; a=rsa-sha256; cv=none; b=rBvcbCMXHVkCbMF7SwWsmkwb8ZCSI+Xd7STAnMkseXBdo3mfBcDZil47AYXcI9FZGEf4tU fsMe0M/fNNp9fEA6wCb1AHAicCc3TEOKCwhr+E+yHIrMsvnXEKQ9qJ137ZonyOymjEXSwM Zuc3bYGM2RCDxJfgOfpIyiT4F7iBWtVeSC92cCDg3hJHXQEZn9VtYjT9B16JboNe7QFJvv vFujHB4i8rBmKhR/NgETVj9Cmm0K0RsnaiYTvIZu2dHN+ccWJ1uo9G6yJ2g7xY8IRrnLWG KORKEmC+1hVrufSSprz1bJ9/tPD0OasMmGI7Tw/CNny7chxOT7KMfyh47JwETw== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1717720022; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Nz58/GMe7o2j4SH/Bmd49EyxSAsL6Xnt0ldcHPYgOns=; b=dIHKGQeM9aM9MMh64SoKvSRjk9Cp13Jrwjl0AabltOHhTg/zNREWCF603ajaRLQUiONCb+ oxsol1PXiOIMGhHlBNsJ6vaNP+dTlIuZNN5MFiMKRXyVS/o4b7Bq5+ucsIUPpNxuiWNtnX bnXWl4Qagmf47faMdfp0dwaRdp0X3oDOXfEU6kPrwCJHmzUcNjyT5Agx4fryoGh6j3R85S 09QSnRMG2LSz3cu7p4UcxXQzy3wB1IX7bl/9BZPetS6sa4Ctabgw71zMud18mq46qbXqda w2nx69OAKmgahU9voZUIhZH3ow3SfY8iHUN8ODBTVDgloreocczJTZ4tPyEyUQ== Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4VwMTL33zCz16wj for ; Fri, 7 Jun 2024 00:27:02 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id 4570R2rS092777 for ; Fri, 7 Jun 2024 00:27:02 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 4570R21g092772 for bugs@FreeBSD.org; Fri, 7 Jun 2024 00:27:02 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 271826] FreeBSD is disastrously slow on a PowerMac G5, freezing at every command Date: Fri, 07 Jun 2024 00:27:02 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: misc X-Bugzilla-Version: 13.2-RELEASE X-Bugzilla-Keywords: needs-qa, performance X-Bugzilla-Severity: Affects Some People X-Bugzilla-Who: jhibbits@FreeBSD.org X-Bugzilla-Status: Open X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated List-Id: Bug reports List-Archive: https://lists.freebsd.org/archives/freebsd-bugs List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-bugs@FreeBSD.org MIME-Version: 1.0 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D271826 --- Comment #36 from Justin Hibbits --- (In reply to Mitch from comment #35) mpc85xx platforms I've personally tested with FreeBSD are the AmigaOne X5000 and AmigaOne A1222. I wrote the mpc85xx timebase sync specifically for tho= se targets, after seeing strange hanging behavior. As for why we want to use memory barriers, we really need just execution barriers (isync), I think, because we need to make sure the timebase is cor= rect before it's unlocked by the BSP. This can only be ensured by using a barri= er between setting the timebase and declaring done (atomic_add_int() of cpu_do= ne). But, yes, a weak memory model does mean we need more explicit syncs where = on strong models they would be implicit (but pay the penalty on all accesses). We really shouldn't need any syncs for tb_ready, because it can be done laz= ily. The only sync we should really need is the cpu_done. Before this timebase sync we used a synchronization mechanism at AP launch time, where we simply "hoped" that they were close enough to all get the sa= me timebase. This is obviously problematic. It was changed during the 12-CUR= RENT time frame. The powermac sync change was done in 2021, though. --=20 You are receiving this mail because: You are the assignee for the bug.=